#include <iostream>
using namespace std;
int main()
{
double x,y;
int n,m=1;
x=3.14159;
cout <<"n=";
do
{
cin>>n;	
}while(n<1||n>5);
for(int i=1;i<=n;i++)
m=m*10;
y=(int)(x*m+0.5);
y=y/m;
cout <<y<<endl;
return 0;	
}
